[Stgt-devel] FirstBurstLenght > MaxBurstLength --> error

[Albert Pauw]

Thanks,

first tests seem to work fine.

Albert

FUJITA Tomonori wrote:
> From: Albert Pauw <albert.pauw at gmail.com>
> Subject: [Stgt-devel] FirstBurstLenght > MaxBurstLength --> error
> Date: Sun, 15 Apr 2007 11:33:27 +0200
> 
>> Running the test regression script of open-iscsi on stgt I found an 
>> error, which I did not encounter with other targets.
>>
>> It is test #17 with the following parameters:
>>
>> ================== TEST #17 BEGIN ====================
>> ImmediateData = No
>> InitialR2T = No
>> HeaderDigest = None
>> DataDigest = None
>> FirstBurstLength = 8192
>> MaxBurstLength = 4096
>> MaxRecvDataSegmentLength = 4096
>> MaxOutstandingR2T = 1
>>
>> I get the error "Invalid burst lengths first_burst 8192 max_burst 4096" 
>> in /var/log/messages and the login breaks of.
>> According to the RFC 3720 "FirstBurstLength MUST NOT exceed 
>> MaxBurstLength" (chap 12.14), which means that the target
>> should answer back with a FirstBurstLenght parameters equal to 
>> MaxBurstLenght.
>>
>> I investigated with wireshark and found that this is exactly the 
>> behaviour of the Wasabi Storagebuilder target,
>> iscsi-target silently accepts FirstBurstLength > MaxBurstLength, and 
>> stgt only gives an error.
> 
> I've attached a patch. It's not pretty but I don't have a better idea.
> 
> 
> diff --git a/usr/iscsi/iscsid.c b/usr/iscsi/iscsid.c
> index 2377952..d973409 100644
> --- a/usr/iscsi/iscsid.c
> +++ b/usr/iscsi/iscsid.c
> @@ -226,8 +226,10 @@ static void login_security_done(struct i
>  static void text_scan_login(struct iscsi_connection *conn)
>  {
>  	char *key, *value, *data;
> -	int datasize, idx;
> +	int datasize, idx, first_burst = 0;
>  	struct iscsi_login_rsp *rsp = (struct iscsi_login_rsp *)&conn->rsp.bhs;
> +	struct param *p = conn->session_param;
> +	char buf[32];
>  
>  	data = conn->req.data;
>  	datasize = conn->req.datasize;
> @@ -240,14 +242,12 @@ static void text_scan_login(struct iscsi
>  		else if (!((idx = param_index_by_name(key, session_keys)) < 0)) {
>  			int err;
>  			unsigned int val;
> -			char buf[32];
>  
>  			if (idx == ISCSI_PARAM_MAX_RECV_DLENGTH)
>  				idx = ISCSI_PARAM_MAX_XMIT_DLENGTH;
>  
>  			if (param_str_to_val(session_keys, idx, value, &val) < 0) {
> -				if (conn->session_param[idx].state
> -				    == KEY_STATE_START) {
> +				if (p[idx].state == KEY_STATE_START) {
>  					text_key_add_reject(conn, key);
>  					continue;
>  				} else {
> @@ -261,9 +261,14 @@ static void text_scan_login(struct iscsi
>  			}
>  
>  			err = param_check_val(session_keys, idx, &val);
> -			err = param_set_val(session_keys, conn->session_param, idx, &val);
> +			if (idx == ISCSI_PARAM_FIRST_BURST &&
> +			    p[idx].state == KEY_STATE_START) {
> +				first_burst = val;
> +				continue;
> +			}
> +			err = param_set_val(session_keys, p, idx, &val);
>  
> -			switch (conn->session_param[idx].state) {
> +			switch (p[idx].state) {
>  			case KEY_STATE_START:
>  				if (idx == ISCSI_PARAM_MAX_XMIT_DLENGTH)
>  					break;
> @@ -272,25 +277,35 @@ static void text_scan_login(struct iscsi
>  				text_key_add(conn, key, buf);
>  				break;
>  			case KEY_STATE_REQUEST:
> -				if (val != conn->session_param[idx].val) {
> +				if (val != p[idx].val) {
>  					rsp->status_class =
>  						ISCSI_STATUS_CLS_INITIATOR_ERR;
>  					rsp->status_detail =
>  						ISCSI_LOGIN_STATUS_INIT_ERR;
>  					conn->state = STATE_EXIT;
> -					log_warning("%s %u %u\n", key,
> -					val, conn->session_param[idx].val);
> +					eprintf("invalid response %s %u %u\n",
> +						key, val, p[idx].val);
>  					goto out;
>  				}
>  				break;
>  			case KEY_STATE_DONE:
>  				break;
>  			}
> -			conn->session_param[idx].state = KEY_STATE_DONE;
> +			p[idx].state = KEY_STATE_DONE;
>  		} else
>  			text_key_add(conn, key, "NotUnderstood");
>  	}
>  
> +	if (first_burst) {
> +		idx = ISCSI_PARAM_MAX_BURST;
> +		if (first_burst > p[idx].val)
> +			first_burst = p[idx].val;
> +		idx = ISCSI_PARAM_FIRST_BURST;
> +		p[idx].state = KEY_STATE_DONE;
> +		param_set_val(session_keys, p, idx, &first_burst);
> +		param_val_to_str(session_keys, idx, first_burst, buf);
> +		text_key_add(conn, "FirstBurstLength", buf);
> +	}
>  out:
>  	return;
>  }
> 
>